Professor Jan Ingo Flege, Applied Physics and Semiconductor Spectroscopy, Institute of Physics, Brandenburg Technical University of Cottbus-Senftenberg, Cottbus, Germany

In situ probing of the growth, structure, and surface chemistry of ultrathin ceria films by low-energy electron microscopy

In situ probing of the growth, structure, and surface chemistry of ultrathin ceria films by low-energy electron microscopy Jan Ingo Flege Applied Physics and Semiconductor Spectroscopy, Institute of Physics/Faculty 01, Brandenburg Technical University of Cottbus-Senftenberg, Cottbus, Germany flege@b-tu.de Cerium oxide is of considerable importance for a wide range of technological applications including, e. g., energy harvesting, storage, and conversion, chemical sensing, and heterogeneous catalysis. Epitaxially grown ceria thin films and nanostructures represent important model systems allowing for the investigation of their peculiar materials properties using surface science methodology.

In this presentation, I will focus on the growth and characterization of cerium oxide ultrathin films and microparticles on transition metal surfaces and the subsequent monitoring of their structural and chemical modifications in reactive environments using low-energy electron microscopy and related methods [1]. Using the frequently employed ceria/Ru(0001) [2] and ceria/Pt(111) [3] inverse model catalysts as primary examples, it will be demonstrated that nanoscale structural transformations that occur upon chemical reduction, thermal annealing, or reoxidation can be followed in real-time [4-6].

[1] J. I. Flege and D. C. Grinter, Prog. Surf. Sci. 93, 21 (2018).
[2] D. C. Grinter, S. D. Senanayake, and J. I. Flege, Appl. Catal., B 197, 286 (2016).
[3] M. Sauerbrey, G. Gasperi, P. Luches, J. Falta, S. Valeri, J. I. Flege, Top. Catal. 60, 513 (2017).
[4] J. Höcker et al., Adv. Mater. Interfaces 2, 1500314 (2015).
[5] J. Höcker, J.-O. Krisponeit, Th. Schmidt, J. Falta, and J. I. Flege, Nanoscale 9, 9352 (2017).
[6] P. Luches, G. Gasperi, M. Sauerbrey, S. Valeri, J. Falta, and J. I. Flege, submitted. 

Host: Associate Professor Jeppe Vang Lauritsen, iNANO & Department of Physics and Astronomy, Aarhus University